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Biomedical subjects

S Yamaki

Publications and source records attributed to S Yamaki.

At least 55 records · Page 3Linked to original sources
PubMed1992

Tetralogy of Fallot with anomalous origin of left pulmonary artery.

Between 1971 and 1990, 7 patients of tetralogy of Fallot with anomalous origin of left pulmonary artery underwent intracardiac repairs at Tohoku University Hospital. They were 2 males and 5 females with ages ranging from 4 to 26 years old. The right pulmonary artery connected to right ventricle in all cases, whereas no communications between right ventricle and the left pulmonary artery were found. The left pulmonary artery directly originated from the ascending aorta in 2 patients (group I) and connected to the ductus arteriosus in 5 patients (group II and III). In 2 patients (group II), the left pulmonary artery was separated from the pulmonary arterial trunk by the intraluminal membrane, receiving blood supply through the ductus. In the remaining 3 patients (group III), there were no continuations between both pulmonary arteries. At the correction, communication between the left pulmonary artery and the pulmonary arterial trunk could be reconstructed in groups I and II. However, it was not possible in group III, because the ductus arteriosus and the left pulmonary artery had already been occluded before the intracardiac repair. In group III, ventricular septal defect was closed using a one-way valved patch or a perforated patch to decrease supersystemic right ventricular pressure. Postoperative right ventricular aortic pressure ratio was between 0.5 and 0.8 in groups I and II, and between 0.8 and 1.0 in group III. Three patients (one in each group) died after the operation. Severe pulmonary vascular obstructive disease was found in the left lung of group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Quantitative analysis of pulmonary vascular disease in total anomalous pulmonary venous connection in sixty infants.

A quantitative analysis of small pulmonary arteries, pulmonary veins, and lymphatic vessels was conducted in autopsy cases of total anomalous pulmonary venous connection. The materials were obtained from 60 cases of total anomalous pulmonary venous connection without asplenia or pulmonary stenosis, ages ranging from 2 days to 19 months at the time of death (mean age 2.2 months). Pulmonary arterial pressure had been measured in 32 of these patients before death. Twenty cases of ventricular septal defect with pulmonary hypertension and 15 normal individuals were used as the control group. The mean thickness of the media of small pulmonary arteries and veins was 12.7 and 7.6 microns, respectively, in the total anomalous pulmonary venous connection cases, both values being significantly larger than those for normal and ventricular septal defect cases. No changes in thickness with aging were found. Medial thickness in the arteries and veins was greater in the cases of pulmonary venous obstruction than in those without such obstruction. The medial thickness of small pulmonary arteries in total anomalous pulmonary venous connection cases correlated with increased pulmonary arterial pressure. When the patients with the same pulmonary arterial pressure levels were compared, the medial thickness was always greater in those who had total anomalous pulmonary venous connection than in those who had ventricular septal defect. The medial thickness of pulmonary veins was also highly correlated with increased pulmonary arterial pressure in total anomalous pulmonary venous connection. The severity of the intimal lesions was milder in those who had total anomalous pulmonary venous connection than in those who had ventricular septal defect, suggesting the protective role of the thickened pulmonary arterial media against development of intimal lesions. Intimal fibrous thickening of pulmonary veins was not seen in the cases of ventricular septal defect, but it was present in 45% of the total anomalous pulmonary venous connection cases. Lymphangiectasia was characteristically present in 62% of the total anomalous pulmonary venous connection cases. Interstitial emphysema was often a complication of lymphangiectasia, and it led to eight postoperative deaths.

Age Factors↗
PubMed1991

[Tetralogy of Fallot with anomalous origin of unilateral pulmonary artery].

Between 1971 and 1988, 7 patients (pts) of TOF with anomalous origin of unilateral pulmonary artery (AOPA) underwent intracardiac repair at Tohoku University Hospital. They were 2 males and 5 females, with ages ranging from 4 to 26 years old. The right PA originated from the RV in all cases, whereas the left PA originated from the ascending aorta in 2 pts (Group 1) and from the ductus arteriosus in 5 pts (Group 2 & 3). In Group 2 (2 pts), the left PA was separated from the right PA with intraluminal membrane. In Group 3 (3 pts), there was no communication between both pulmonary arteries. The left PA was reconstructed in Group 1 & 2. However, it was impossible to reconstruct the left PA in Group 3 since the ductus arteriosus and left PA had been occluded before intracardiac repair. In Group 3, VSD was closed with one-way (RV----LV) valved patch for the aim of lowering RV pressure. Postoperative RV/Ao pressure ratio was 0.5-0.8 in the cases of Group 1 & 2, 0.8-1.0 in Group 3. Three patients (one in each group) died postoperatively due to low output syndrome. Autopsy revealed pulmonary vascular obstructive disease (PVOD) of the left lung in Group 1. It is concluded that TOF with AOPA should be corrected before the advance of PVOD in case PA originate from the ascending aorta, and before the occlusion of the ductus in case PA originate from it, in order to prevent postoperative RV overload.

Adolescent↗
PubMed1990

Indications for open lung biopsy in patients with ventricular septal defect and/or patent ductus arteriosus with pulmonary hypertension.

In a previous paper, it was stated that open lung biopsy for determination of operative indications could be recommended if pulmonary vascular resistance (PVR) were higher than 8 units.m2 in patients with ventricular septal defect (VSD) and/or patent ductus arteriosus (PDA) with severe pulmonary hypertension. In the present study, oxygen inhalation or Tolazoline administration tests with or without occlusion of ductus arteriosus were performed during cardiac catheterization in 47 patients with VSD and/or PDA with severe pulmonary hypertension. The results obtained were compared with the operability based on our histopathological diagnostic criteria. There was no correlation between the oxygen, Tolazoline, or ductus occlusion hemodynamics and the baseline hemodynamics for better prediction of the biopsy should be performed for the determination of operative indication when patients with VSD and/or PDA have a PVR higher than 8 units.m2, and if the PVR is greater than 4 units.m2 with the oxygen inhalation test or 7 units.m2 with the Tolazoline test.

Adult↗
PubMed1990

Pulmonary vascular disease in shunted and nonshunted patients with tetralogy of Fallot.

Histometric analysis of pulmonary vascular disease was performed in 13 shunted and 21 nonshunted patients with tetralogy of Fallot, and in 29 normal controls. There was no significant difference in the medial thickness of the small pulmonary arteries between cases of tetralogy of Fallot and normal controls, but the media in shunted cases of tetralogy of Fallot were thicker than in the nonshunted cases. Intimal fibrosis, regarded as organized thrombi, and thrombi of small pulmonary arteries were observed generally after 4 years of age in both the shunted and nonshunted cases of tetralogy of Fallot. Intimal proliferation of musculoelastosis which was formed of longitudinal smooth muscle bundles and elastic fibers was characteristic in shunted patients, especially after the central palliation procedure, Waterston anastomosis or modified Blalock-Taussig (BT) anastomosis using the Gore-Tex tube graft. However, it was not usually seen in the BT anastomosis cases. Unexpected pulmonary hypertension due to the shunt operation is thought to be the cause of musculoelastosis, because musculoelastosis was observed even in a patient with pulmonary hypertension only 3 weeks following surgery. We therefore recommend the original BT anastomosis as the shunt procedure. When considering the use of other shunt operations in which there is a possibility of placing a pressure load on the pulmonary vascular bed, attention must be given to the size of the anastomosis or artificial tube graft.

Child, Preschool↗
PubMed1990

[A new experimental model of pulmonary hypertension in dog using an adjustable pulmonary artery band].

In order to study pathogenesis, reversibility, and treatment of pulmonary hypertension in congenital heart disease, a new experimental model to induce pulmonary vascular diseases has been designed. Previous models by other investigators were anastomosis between a systemic artery and pulmonary artery of one lung lobe, and these could not provide constant induction of pulmonary vascular diseases. Furthermore the postoperative mortalities in their experiences were quite high and acute iatrogenic pathological changes such as bleeding, edema and emphysema developed in the pulmonary vasculature and parenchyma of the anastomosed lobe. Use of our adjustable pulmonary artery band has eliminated such unwanted complications. The surgical procedure includes an end-to-side anastomosis of the left main pulmonary artery to the descending thoracic aorta, and banding of the anastomosed pulmonary artery using the adjustable band. The band was gradually loosened by extrathoracic manipulation during three to four weeks observation after operation. This technique provided dogs to survive sufficiently long enough and with a high success rate, and to produce extremely advanced pulmonary vascular diseases. Of the twenty dogs operated such, eighteen survived the first postsurgical week and thirteen dogs developed hypertensive pulmonary vascular diseases. Development of the medial hypertrophy was evident at one week and gradually advanced. In eight weeks, intimal cellular proliferation (Grade 2 of the Heath & Edwards' classification) became apparent. In twelve weeks, the intimal proliferation became fibrous and acellular (Grade 3) and caused complete obstruction of the lumen of some muscular arteries. In twenty weeks specimen, typical plexiform lesions (Grade 4) and dilatation lesions (Grade 5) involved the small muscular arteries in the whole left lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Surgical management of open lung biopsy in Eizenmenger's syndrome].

Three of 254 patients with Eizenmenger's syndrome had complications, namely bleeding during and after surgery of open lung biopsy. Histopathologic study of the lung in patients suffering from complications revealed that destruction of the collateral vessels characterized by wide lumen and weak walls is responsible for the postoperative bleeding. Such complications can be prevented by using the TA stapler which cuts off the lung tissue with little or no damage to the other lung tissues.

Adult↗
PubMed1990

[A case of massive hemoglobinuria due to patch dehiscence--following patch closure of ventricular septal defect].

A three-month-old baby with persistent intravascular hemolytic anemia following patch closure of subpulmonic ventricular septal defect was reported. Mechanical hemolysis was diagnosed by the presence of blood cell fragments and schistocytes in peripheral blood smear. It was thought that destruction of red cells developed by turbulent flows and direct contact of red blood cells with bared rough surfaces of the teflon patch at the site of dehiscence. When the cause of severe hemolysis was attributed to inadequate intracardiac repairs, immediate second surgical intervention should be performed.

Female↗
PubMed1989

Indications for surgery based on lung biopsy in cases of ventricular septal defect and/or patent ductus arteriosus with severe pulmonary hypertension.

Pathologic obstruction of the proximal lumen and secondary atrophy of the media of the peripheral small pulmonary arteries were absolute operative contraindications in cases of VSD and/or PDA with severe pulmonary hypertension. Such patients who were operated on died with no decrease in pulmonary arterial pressure. The index of pulmonary vascular disease (IPVD), a composite and quantitative evaluation of the severity of pulmonary vascular disease, was introduced to determine the operability of other patients. An IPVD rating of 2.2 in Down's syndrome and 2.1 without the syndrome were regarded as the upper permissible limits for surgical intervention based on results of 23 autopsies and 26 lung biopsies of patients operated on before 1981. Open lung biopsy was performed in 51 patients to determine applicability of our operative indications. Twenty-nine cases were considered operable by our criteria, and 28 underwent surgical correction without operative or late death. Twenty-two cases thought inoperable remain under observation. Comparative analysis of the pathology and preoperative hemodynamic data suggested that lung biopsy should be carried out to determine operability in cases with pulmonary vascular resistance greater than 8 units.m2.

Biopsy↗
PubMed1989

[Pulmonary vascular disease in shunted and nonshunted patients with tetralogy of Fallot].

Histometric analysis of pulmonary vascular disease was performed in 21 nonshunted patients and in 13 shunted patients with tetralogy of Fallot and in 29 normal controls. There was no significant difference in the medial thickness of the small pulmonary arteries between cases of tetralogy of Fallot and normal controls. However, the media in the shunted cases of tetralogy of Fallot gave the impression of being thicker than these in the nonshunted cases. Intimal fibrosis, regarded as organized thrombi, and thrombi of small pulmonary arteries were observed generally after 4 years of age in shunted and nonshunted cases of tetralogy of Fallot. Intimal proliferation of musculoelastosis which was formed longitudinal smooth muscle bundles and elastic fibers was characteristic in shunted patients, especially after the central palliation procedure, Waterston anastomosis and modified Blalock-Taussig (B-T) anastomosis using a Gore-Tex tube graft. However, musculoelastosis was not usually seen in the B-T anastomosis cases. Unexpected pulmonary hypertension due to shunt operation is thought to be the cause of musculoelastosis, because musculoelastosis was observed even in a patient with pulmonary hypertension 3 weeks following surgery. We, therefore, recommend original B-T anastomosis as the shunt procedure. When considering use of the other shunt operations which entail pressure load on the pulmonary vascular bed, attention must be given to the size of the anastomosis or artificial tube graft.

Adolescent↗
PubMed1989

[Clinical experience of autotransfusion system (ATS)--changes in free hemoglobin and haptoglobin].

This study was done to evaluate the usefulness of ATS and the administration of haptoglobin, and is comprised of 15 patients following open heart surgery. Shed mediastinal blood was retransfused during 4-6 hours after open heart surgery. Plasma free Hb (F-Hb) value of the shed blood was 647 mg/dl. But plasma F-Hb of patient did not significantly increase after retransfusion of shed blood without administration of haptoglobin. Plasma F-Hb of patient decreased significantly from 12 mg/dl to 3.3 mg/dl when haptoglobin was given. (p less than 0.05). There was no serious complication associated with the use of ATS, and could save 300 ml of homologous blood. It is concluded that ATS can be used safely for saving homologous blood after open heart surgery and haptoglobin is effective for decreasing of plasma F-Hb.

Blood Transfusion, Autologous↗
PubMed1989

[Improvement of operative result of Stanford type A aortic dissection].

21 cases of Stanford type A aortic dissection (15 acute and 6 chronic) were treated with or without surgery in the last 38 months. Out of seven cases who were admitted before October, 1986, three cases were treated medically and all died suddenly within 30 days. The remaining four cases were operated upon as emergency with only one survival. Extensive hemorrhage was the cause of operative deaths. After November 1986, substantial reduction in hospital mortality (one death in eight acute cases) was accomplished by the following strategy for acute aortic dissection, i.e., (1) urgent operative intervention for cases with cardiac involvement, and initial medical treatment followed by elective operation at chronic stage for those without cardiac involvement, (2) routine use of open distal anastomosis, (3) preferential adoption of simple surgical intervention limited to the ascending aorta. There was no operative death in six chronic cases in spite of more extensive approach. These results suggest that the strategy mentioned above is reasonable in treatment for Stanford type A dissecting aneurysm.

Adult↗
PubMed1989

[Unilateral pulmonary venous obstruction: a case report].

A 3-month-old girl with right common pulmonary venous obstruction and severe pulmonary hypertension underwent pulmonary venous reconstruction (venoplasty). However, pulmonary hypertension persisted and she died on the 69th postoperative day. Autopsy revealed a widely opened pulmonary vein at the site of the venoplasty. Histological examination showed thickened alveolar walls, thromboembolism in pulmonary arterioles and venous hypoplasia in the right lung. The venoplasty for unilateral pulmonary venous obstruction with severe pulmonary hypertension may not be the proper treatment, since pulmonary hypertension usually continues or progresses postoperatively. Pneumonectomy may be a better choice to be applied.

Child, Preschool↗
PubMed1988

Surgical closure of ventricular septal defect in the first year of life: forty-three consecutive successful cases.

Forty-three infants (less than 12 months of age) underwent VSD closure without operative mortality between June 1982 and December 1987. Average age and body weight at the operation were 6.9 months and 5.3 kg, respectively. Associated cardiac anomalies were PDA (11 patients), ASD (5) and PS (1). Preoperative pulmonary to systemic peak pressure ratio (Pp/Ps), resistance ratio and flow ratio, and pulmonary vascular resistance were 0.79 +/- 0.15, 0.29 +/- 0.16, 2.52 +/- 0.60 and 3.05 +/- 1.94 unit.m2, respectively. VSD was closed under combined surface/perfusion hypothermia with total circulatory arrest in 25 patients and standard cardiopulmonary bypass in 18. All patients were discharged from the hospital in good condition, but there was one late death due to pneumonia. Postoperative Pp/Ps decreased to 0.39 +/- 0.11. Most of the patients demonstrated satisfactory body weight gain after VSD closure. These results support our current policy of aggressive surgical intervention for refractory VSD in the early stage of life.

Cardiac Surgical Procedures↗
PubMed1987

Secundum atrial septal defect with severe pulmonary hypertension. Open lung biopsy diagnosis of operative indication.

In 14 of 15 patients ranging in age from 1 to 62 years (mean of 34) with secundum atrial septal defect (ASD) and pulmonary hypertension over 60 mm Hg peak pressure, operative indication was determined by morphometric diagnosis of open biopsy of lung specimens. In one patient, open lung biopsy was also performed during corrective surgery. Pulmonary arterial changes in the 15 patients were grouped into four classifications as follow: (1) plexogenic pulmonary arteriopathy (six patients); (2) thromboembolism in small pulmonary arteries (three patients); (3) "musculoelastosis," intimal proliferation of longitudinal smooth muscle bundles and elastic fibers (three patients); and (4) combinations of (1), (2) or (1), (3) (three patients). We conclude concerning the operative indication that group 2 patients are operable in all cases and group 1 patients with Yamaki's index of pulmonary vascular disease of 2.2 or less; group 3 patients with the absence of complete occlusion of the small pulmonary arterial lumen are operable, and patients with clear evidence of severe plexogenic pulmonary arteriopathy in group 4 are not operable. Comparative analysis of pulmonary pathology and hemodynamic performance revealed that open lung biopsy should be performed to determine operative candidacy in cases with a pulmonary vascular resistance greater than 8 unit X m2, which is considered to represent the borderline of operability.

Adult↗